Extruder with non-stop die change device and method of using same

ABSTRACT

An extruder with a non-stop die change device includes an extrusion cavity, a die change device located at the outlet of the extrusion cavity, and a first die and a second die that are connected to the side wall of a housing of the die change device. A transfer channel is provided in a movable block of the die change device. When the movable block moves to a first position in the housing, the transfer channel communicates to the extrusion cavity with a first channel, and when the movable block moves to a second position in the housing, the transfer channel communicates to the extrusion cavity with a second channel. Therefore, die change and product type change can be achieved without stopping the extruder. If a die is blocked, the extruder does not need to stop for changing a new die.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 16/185,339, filed Nov. 9, 2018, now allowed, which is acontinuation application of International Patent Application No.PCT/CN2017/099624, filed Aug. 30, 2017, which itself claims the priorityto Chinese Patent Application Nos. CN201710329050.8 andCN201710329046.1, both filed May 11, 2017 in the State IntellectualProperty Office of P.R. China, which are hereby incorporated herein intheir entireties by reference.

FIELD OF THE INVENTION

The invention relates generally to the field of food and feeds, and moreparticularly, to an extruder with a non-stop die change device and amethod of using the same for processing pet food, human food and aquaticfeeds.

BACKGROUND OF THE INVENTION

The background description provided herein is for the purpose ofgenerally presenting the context of the invention and is neitherexpressly nor impliedly admitted as prior art against the invention. Thesubject matter discussed in the background of the invention sectionshould not be assumed to be prior art merely as a result of its mentionin the background of the invention section. Similarly, a problemmentioned in the background of the invention section or associated withthe subject matter of the background of the invention section should notbe assumed to have been previously recognized in the prior art. Thesubject matter in the background of the invention section merelyrepresents different approaches, which in and of themselves may also beinventions.

Extruders are usually used in the food and feed industries in order toprocess high cured products. However, the current extrusion productionline has shortcomings. For example, the extruders have low operationefficiency, where changing dies and varieties of products take a longtime.

Extruded products in the food and feed industries have many formulas,generally 10-15 formulas. They may have 20-30 formulas, or even more.There are also multiple specifications of dies, generally at least morethan 10 dies. Combinations of different formulas with different dies mayresult in over 200 products.

Usually, an extrusion production line often produces 3 to 8 differentproducts a day. Every time when a product is changed, it needs to stopthe extruder, detach the die, clean the extruder, install another dieand then start the extruder. Such a process takes a long time, generally30 to 60 minutes. If the operator is unskilled, the time for changingthe product may take 120 minutes or more.

In addition to the varieties of products, the die of the extruder isoften blocked by fibers and impurities in the raw materials during theproduction process. After the die is blocked, the granules are deformedand the productivity is reduced. The only way to solve this problem isto stop the machine and replace the die. It also needs to detach thedie, clean the extruder, install another die and then start the extruderduring each stop for replacing the die. A quite long time is taken.

Due to the above factors, the efficiency of the effective operation ofthe extruder is quite low. This challenge with the need to solve theproblem is that the rapid die change requires a rapid knife hood changeand both knife hoods are necessary when a product is flowing throughboth dies simultaneously.

Therefore, a heretofore unaddressed need exists in the art to addressthe aforementioned deficiencies and inadequacies.

SUMMARY OF THE INVENTION

One of the objectives of the invention is to solve the above problems byproviding an extruder with a non-stop die change device, in which aplurality of dies can be used at the same time, the dies can be changedwithout being detached, and meanwhile, the extruder does not need tostop during the die change. In addition, the invention further providesa method of using the above extruder.

In one aspect of the invention, the extruder with a non-stop die changedevice includes an extrusion cavity, a feeding port located at the upperpart in the extrusion cavity, and a die change device located at theoutlet of the extrusion cavity; a conveyor for conveying a material tothe die change device is arranged in the extrusion cavity; the diechange device includes a housing, a movable block located in thehousing, a driving device for driving the movable block, a first dieconnected to the side wall of the housing, and a second die connected tothe side wall of the housing. The first die is provided with a firstchannel that penetrates the first die and communicates with the interiorof the housing. The second die is provided with a second channel thatpenetrates the second die and communicates with the interior of thehousing. The outlet of the extrusion cavity is connected to the sidewall of the housing and communicates with the interior of the housing. Atransfer channel is provided in the movable block, and the movable blockis driven by the driving device to move at a first position to a secondposition. When the movable block moves to the first position in thehousing, the transfer channel communicates to the extrusion cavity withthe first channel. When the movable block moves to the second positionin the housing, the transfer channel communicates to the extrusioncavity with the second channel.

The extruder with the non-stop die change device has the advantages ofwhich, by driving the movable block, the extrusion cavity cancommunicate with different dies without stopping, when the productvariety is changed, and if a die is blocked, the die does not need to bereplaced with a new die by stopping the operation. It is noted that onlytwo dies are given in the above exemplary embodiment. It should beappreciated that two or more dies can also be utilized to practice theinvention.

The movable block is a piston or a rotating block that rotates in thehousing.

In one embodiment, when a piston located inside the housing is selectedas the movable block; at least one first transfer channel and at leastone second transfer channel are provided in the piston; when the pistonmoves to the first position in the housing, the first transfer channelcommunicates to the extrusion cavity with the first channel; and whenthe piston moves to the second position in the housing, the secondtransfer channel communicates to the extrusion cavity with the secondchannel.

In another aspect, the invention also provides the method of using theextruder with the non-stop die change device when a piston is used asthe movable block. When only the first die is used for production, thedriving device forces the piston to move to the first position, thefirst transfer channel communicates to the extrusion cavity with thefirst channel, and the material is conveyed into the first die throughthe conveyor in the extrusion cavity. When only the second die is usedfor production, the driving device forces the piston to move to thesecond position, the second transfer channel communicates to theextrusion cavity with the second channel, and the material is conveyedinto the second die through the conveyor in the extrusion cavity.

In one embodiment, at least one third transfer channel is provided inthe piston; when the piston moves to a third position in the housing,the third transfer channel communicates to the extrusion cavity with thefirst channel and the second channel simultaneously. According to theinvention, the first die and the second die (or more dies) can be usedat the same time, which can expand the application of the extruder, andproduce two or more kinds of products at the same time.

As for the extruder with the third transfer channel, the invention alsoprovides a method of using the extruder, that is, when only the firstdie is used for production, the driving device forces the piston to moveto the first position, the first transfer channel communicates to theextrusion cavity with the first channel, and the material is conveyedinto the first die through the conveyor in the extrusion cavity; whenonly the second die is used for production, the driving device forcesthe piston to move to the second position, the second transfer channelcommunicates to the extrusion cavity with the second channel, and thematerial is conveyed into the second die through the conveyor in theextrusion cavity; and when the first die and the second die aresimultaneously used for production, the driving device forces the pistonto move to the third position, the third transfer channel communicatesto the extrusion cavity with the first channel and the second channel atthe same time, and the material is simultaneously conveyed into thefirst die and the second die through the conveyor in the extrusioncavity.

In one embodiment, the first transfer channel includes a first inlet anda first outlet, the second transfer channel includes a second inlet anda second outlet, and the side wall of the housing is provided with afeeding port for connecting the interior of the housing with the outletof the extrusion cavity, a first discharging port for connecting theinterior of the housing with the first transfer channel and a seconddischarging port for connecting the interior of the housing with thesecond transfer channel.

When the mechanical energy borne by the material needs to be adjusted,the invention provides the following technical solution. When only thefirst die is used for production and adjusting the mechanical energyborne by the material, the driving device forces the piston to move sothat the first transfer channel communicates to the extrusion cavitywith the first channel, at this time, the first inlet is in misalignmentcommunication with the feeding port on the housing, and the material isconveyed from the feeding port to the first inlet through the conveyorin the extrusion cavity and conveyed into the first die through thefirst outlet; and when only the second die is used for production andadjusting the mechanical energy borne by the material, the drivingdevice forces the piston to move so that the second transfer channelcommunicates to the extrusion cavity with the second channel, at thistime, the second inlet is in misalignment communication with the feedingport on the housing, and the material is conveyed from the feeding portto the second inlet through the conveyor in the extrusion cavity andconveyed into the second die through the second outlet.

According to the method, when a certain die is used, the feeding port ismisaligned with a certain inlet, that is, a formed channel opening isactually smaller than the feeding port, the resistance formed by thematerial at the channel opening becomes large, and if the degree ofmisalignment is larger, the resistance is larger and the mechanicalenergy borne by the material is also larger. The mechanical energy borneby the material can be adjusted by adjusting the size of the channelopening.

Based on the same principle, when at least one third transfer channel isprovided in the piston, the first die and the second die aresimultaneously used for production and adjusting the mechanical energyborne by the material, the driving device forces the piston to move, thethird transfer channel communicates to the extrusion cavity with thefirst channel and the second channel simultaneously, at this time, thethird inlet is in misalignment communication with the feeding port onthe housing, and the material is conveyed from the feeding port to thethird inlet through the conveyor in the extrusion cavity and conveyedinto the first die and the second die simultaneously through two thirdoutlets.

In one embodiment, when a rotating block is selected, the block willrotate as it aligns the channel with the first position in the housing,a first port communicates with the extrusion cavity, and a second portcommunicates with the first channel; and when the rotating block rotatesto the second position in the housing, the second port communicates withthe extrusion cavity, and the first port communicates with the secondchannel.

According to the embodiment, when a rotating block is used as themovable block, the method of using the above extruder with the non-stopdie change device includes: when only the first die is used forproduction, the driving device drives the rotating block to rotate tothe first position, the first port communicates with the extrusioncavity, the second port communicates with the first channel, and thematerial is conveyed into the first die through the conveyor in theextrusion cavity; and when only the second die is used for production,the driving device drives the rotating block to rotate to the secondposition, the second port communicates with the extrusion cavity, thefirst port communicates with the second channel, and the material isconveyed into the second die through the conveyor in the extrusioncavity.

The extruder further includes a three-way rotating block that replacesthe rotating block; after the three-way rotating block replaces therotating block, it is also driven by the driving device to rotate in thehousing; the three-way rotating block is provided with a three-waytransfer channel, including a channel I, and a channel II and a channelIII that communicate with the channel I at the same time; and when thethree-way rotating block rotates in the housing till the channel Icommunicates with the extrusion cavity, the channel II communicates withthe first channel and the channel III communicates with the secondchannel. The further technical feature achieves the effect of using thefirst die and the second die at the same time, expands the applicationof the extruder, and can produce two or more kinds of products at thesame time.

As for the extruder with the three-way rotating block, the inventionalso provides a method of using the extruder, that is, when the firstdie and the second die are simultaneously used for production, therotating block is replaced with the three-way rotating block, and whenthe driving device drives the three-way rotating block to rotate tillthe channel I communicates with the extrusion cavity, the channel IIcommunicates with the first channel and the channel III communicateswith the second channel.

In one embodiment, the side wall of the housing is provided with afeeding port for connecting the interior of the housing with the outletof the extrusion cavity, a first discharging port for connecting theinterior of the housing with the first transfer channel and a seconddischarging port for connecting the interior of the housing with thesecond transfer channel.

When the mechanical energy borne by the material needs to be adjusted,the invention provides the following technical solution of a usingmethod. When only the first die is used for production and adjusting themechanical energy borne by the material, the driving device drives therotating block to rotate so that the first port communicates with theextrusion cavity, the second port communicates with the first channel,at this time, the first port is in misalignment communication with thefeeding port on the housing, and the material is conveyed from thefeeding port to the first port through the conveyor in the extrusioncavity and conveyed into the first die through the second port; and whenonly the second die is used for production and adjusting the mechanicalenergy borne by the material, the driving device drives the rotatingblock to rotate so that the second port communicates with the extrusioncavity, the first port communicates with the second channel, at thistime, the second port is in misalignment communication with the feedingport on the housing, and the material is conveyed from the feeding portto the second port through the conveyor in the extrusion cavity andconveyed into the second die through the first port.

According to the method, when a certain die is used, the feeding port ismisaligned with a certain port, that is, a formed channel opening isactually smaller than the feeding port, the resistance formed by thematerial at the channel opening becomes large, and if the degree ofmisalignment is larger, the resistance is larger and the mechanicalenergy borne by the material is also larger. The mechanical energy borneby the material can be adjusted by adjusting the size of the channelopening.

Based on the same principle, when the first die and the second die aresimultaneously used for production and adjusting the mechanical energyborne by the material, the rotating block is replaced with a three-wayrotating block and the driving device drives the three-way rotatingblock to rotate till the channel I communicates with the extrusioncavity, the channel II communicates with the first channel and thechannel III communicates with the second channel; at this time, thechannel I is in misalignment communication with the feeding port on thehousing, and the material is conveyed from the feeding port to thechannel I through the conveyor in the extrusion cavity and conveyed tothe first die through the channel II; and the material is conveyed tothe second die through the channel III.

In one embodiment, the extruder also includes a first cutting deviceconnected with the first die, a second cutting device connected with thesecond die, a first air duct connected with the first cutting device,and a second air duct connected with the second cutting device. Thecutting devices are used separately corresponding to different dies.

In one embodiment, the extruder also includes a three-way valveconnected with the first air duct and the second air duct at the sametime; the three-way valve is provided with a first inlet, a second inletand a switch valve outlet, the first inlet communicates with the firstair duct, and the second inlet communicates with the second air duct.

In one embodiment, the three-way switch includes a switch plate locatedbetween the two inlets and the switch valve outlet and a driving devicefor driving the switch plate, and the switch plate is provided with afirst channel port and a second channel port; when the first inlet isused, the switch plate is driven to enable the first channel port to bealigned with the first inlet, and the switch plate blocks the secondinlet; when the first inlet and the second inlet are usedsimultaneously, the driving device drives the switch plate to moveforward, so that the first channel port is aligned with the second inletand the second channel port is aligned with the first inlet; and whenthe second inlet is used, the driving device continues to drive theswitch plate to move forward, the second channel port is aligned withthe second inlet, and the switch plate blocks the first inlet.

In one embodiment, the first air duct includes a first vertical air ductconnected with the first cutting device and extending upward from thefirst cutting device, a first bend connected to the upper end of thefirst vertical air duct and bent to the horizontal direction, and afirst horizontal air duct connected to the horizontal end of the firstbend and continuously horizontally extending to connect with the firstinlet; and the second air duct includes a second vertical air ductconnected with the second cutting device and extending upward from thesecond cutting device, a second bend connected to the upper end of thesecond vertical air duct and bent to the horizontal direction, and asecond horizontal air duct connected to the horizontal end of the secondbend and continuously horizontally extending to connect with the secondinlet. The further technical feature is characterized in that anextruded product coming out of the die, along with a large amount ofvapor, is pneumatically conveyed to next process. Because such a workingcondition is in negative pressure, the leakage of on-site vapor isavoided. In addition, since the granules do not fall freely but arepneumatically conveyed, the granules do not touch each other, and theproblems of granule deformation and adhesion are not produced.

The objectives of the invention are to provide a novel extruder withnon-stop die change device aiming at the deficiencies of the prior art,and the excellent effects of the invention are verified through relevanttest data, in which the product variety can be changed without stop, andif a die is blocked, the extruder also does not need to stop forreplacing a new die. After the application of the present technology,the production efficiency of the extrusion production line can beimproved from current 56-60% to 80% or above, that is, the productionefficiency of the extrusion production line is greatly improved. Inaddition, the problems of pollution of water vapor to the environmentand granule adhesion caused by condensed water are also well solved, andthe adhered granules are thoroughly avoided from original 2-5%.

These and other aspects of the invention will become apparent from thefollowing description of the preferred embodiment taken in conjunctionwith the following drawings, although variations and modificationstherein may be effected without departing from the spirit and scope ofthe novel concepts of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate one or more embodiments of theinvention and together with the written description, serve to explainthe principles of the invention. Wherever possible, the same referencenumbers are used throughout the drawings to refer to the same or likeelements of an embodiment.

FIG. 1 is a side view of an extruder with the non-stop die change deviceaccording to Embodiment 1 of the invention.

FIG. 2 is an inlet view of the extruder with the non-stop die changedevice according to Embodiment 1 of the invention.

FIG. 3 is a top view of the extruder with the non-stop die change deviceaccording to Embodiment 1 of the invention.

FIG. 4 is a three-dimensional view of the extruder with the non-stop diechange device according to Embodiment 1 of the invention.

FIG. 5 is a sectional view of a die change device part of the extruderwith the non-stop die change device according to Embodiment 1 of theinvention.

FIG. 6 is a front view of the die change device of the extruder with thenon-stop die change device according to Embodiment 1 of the invention.

FIG. 7 is a longitudinal sectional view of the die change device in FIG.6 and shows the working state of die A.

FIG. 8 is a transverse sectional view of the die change device in FIG. 6and shows the working state of die A.

FIG. 9 is a structure diagram of a piston according to Embodiment 1 ofthe invention and shows a 2-position die change+1-position dual diepiston.

FIG. 10 is a longitudinal sectional view of the die change device inFIG. 6 and shows the working state of die B.

FIG. 11 is a transverse sectional view of the die change device in FIG.6 and shows the working state of die B.

FIG. 12 is a longitudinal sectional view of the die change device inFIG. 6 and shows the state when the die A and the die B worksimultaneously.

FIG. 13 is a transverse sectional view of the die change device in FIG.6 and shows the state when the die A and the die B work simultaneously.

FIG. 14 is a longitudinal sectional view of the die change device inFIG. 6 and shows the state when the die A works and adjusts themechanical energy borne by the material.

FIG. 15 is a structure diagram of a 2-position die change piston.

FIG. 16 is a structure diagram of a 3-position die change+1-positiondual die piston.

FIG. 17 is a structure diagram of a 3-position die change piston.

FIG. 18 is a structure diagram of a 4-position die change+1-positiondual die piston.

FIG. 19 is a structure diagram of a three-way valve in Embodiment 1 andshows the state of an inlet Ain operation.

FIG. 20 is a structure diagram of a three-way valve in Embodiment 1 andshows the state of an inlet A and an inlet B in simultaneous operation.

FIG. 21 is a structure diagram of a three-way valve in Embodiment 1 andshows the state of an inlet B in operation.

FIG. 22 is a front view of an extruder with the non-stop die changedevice according to Embodiment 2 of the invention.

FIG. 23 is a left view of the extruder with the non-stop die changedevice according to Embodiment 2 of the invention.

FIG. 24 is a top view of the extruder with the non-stop die changedevice according to Embodiment 2 of the invention.

FIG. 25 is a sectional view of a die change device part of the extruderwith the non-stop die change device according to Embodiment 2 of theinvention.

FIG. 26 is a front view of the die change device of the extruder withthe non-stop die change device according to Embodiment 2 of theinvention.

FIG. 27 is a sectional view of the die change device in FIG. 26 .

FIG. 28 is a transverse sectional view of the die change deviceincluding a rotating block in FIG. 27 and shows the working state of dieA.

FIG. 29 is a transverse sectional view of the die change deviceincluding a rotating block in FIG. 27 and shows the state when the die Aworks and adjusts the mechanical energy borne by the material.

FIG. 30 is a transverse sectional view of the die change deviceincluding a rotating block in FIG. 27 and shows the working state of dieB.

FIG. 31 is a transverse sectional view of the die change deviceincluding a rotating block in FIG. 27 and shows the state when the die Bworks and adjusts the mechanical energy borne by the material.

FIG. 32 is a transverse sectional view of the die change device in FIG.27 , replaces the rotating block with a three-way rotating block, andshows the state when the die A and the die B work simultaneously.

FIG. 33 is a transverse sectional view of the die change device in FIG.27 , replaces the rotating block with a three-way rotating block, andshows the state when the die A and the die B work simultaneously andadjust the mechanical energy borne by the material.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be described more fully hereinafter withreference to the accompanying drawings, in which exemplary embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this invention will be thorough and complete, and will fully conveythe scope of the invention to those skilled in the art. Like referencenumerals refer to like elements throughout.

The terms used in this specification generally have their ordinarymeanings in the art, within the context of the invention, and in thespecific context where each term is used. Certain terms that are used todescribe the invention are discussed below, or elsewhere in thespecification, to provide additional guidance to the practitionerregarding the description of the invention. For convenience, certainterms may be highlighted, for example using italics and/or quotationmarks. The use of highlighting has no influence on the scope and meaningof a term; the scope and meaning of a term is the same, in the samecontext, whether or not it is highlighted. It will be appreciated thatsame thing can be said in more than one way. Consequently, alternativelanguage and synonyms may be used for any one or more of the termsdiscussed herein, nor is any special significance to be placed uponwhether or not a term is elaborated or discussed herein. Synonyms forcertain terms are provided. A recital of one or more synonyms does notexclude the use of other synonyms. The use of examples anywhere in thisspecification including examples of any terms discussed herein isillustrative only, and in no way limits the scope and meaning of theinvention or of any exemplified term. Likewise, the invention is notlimited to various embodiments given in this specification.

It will be understood that, as used in the description herein andthroughout the claims that follow, the meaning of “a”, “an”, and “the”includes plural reference unless the context clearly dictates otherwise.Also, it will be understood that when an element is referred to as being“on” another element, it can be directly on the other element orintervening elements may be present therebetween. In contrast, when anelement is referred to as being “directly on” another element, there areno intervening elements present. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of the invention.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top,” may be used herein to describe one element's relationship toanother element as illustrated in the figures. It will be understoodthat relative terms are intended to encompass different orientations ofthe device in addition to the orientation depicted in the figures. Forexample, if the device in one of the figures is turned over, elementsdescribed as being on the “lower” side of other elements would then beoriented on “upper” sides of the other elements. The exemplary term“lower”, can therefore, encompasses both an orientation of “lower” and“upper,” depending of the particular orientation of the figure.Similarly, if the device in one of the figures is turned over, elementsdescribed as “below” or “beneath” other elements would then be oriented“above” the other elements. The exemplary terms “below” or “beneath”can, therefore, encompass both an orientation of above and below.

It will be further understood that the terms “comprises” and/or“comprising,” or “includes” and/or “including” or “has” and/or “having”,or “carry” and/or “carrying,” or “contain” and/or “containing,” or“involve” and/or “involving, and the like are to be open-ended, i.e., tomean including but not limited to. When used in this invention, theyspecify the presence of stated features, regions, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, regions, integers,steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and theinvention, and will not be interpreted in an idealized or overly formalsense unless expressly so defined herein.

As used herein, “around”, “about” or “approximately” shall generallymean within 20 percent, preferably within 10 percent, and morepreferably within 5 percent of a given value or range. Numericalquantities given herein are approximate, meaning that the term “around”,“about” or “approximately” can be inferred if not expressly stated.

As used herein, the phrase “at least one of A, B, and C” should beconstrued to mean a logical (A or B or C), using a non-exclusive logicalOR.

The description below is merely illustrative in nature and is in no wayintended to limit the invention, its application, or uses. The broadteachings of the invention can be implemented in a variety of forms.Therefore, while this invention includes particular examples, the truescope of the invention should not be so limited since othermodifications will become apparent upon a study of the drawings, thespecification, and the following claims. It should be understood thatone or more steps within a method may be executed in different order (orconcurrently) without altering the principles of the invention.

Embodiments of the invention are illustrated in detail hereinafter withreference to accompanying drawings. For purposes of clarity, the samereference numbers will be used in the drawings to identify similarelements.

Embodiment 1

FIGS. 1-21 show a first embodiment (i.e., Embodiment 1) of an extruderwith the non-stop die change device according to the invention.

Referring to FIGS. 1-14 , in Embodiment 1, an extruder includes a base12 for supporting the entire extruder, and a motor 1 directly connectedwith the base 12. The motor is directly connected with a gearbox 2. Thegearbox 2 is connected with a long housing-shaped multi-sectionextrusion cavity 4. A feed extrusion cavity 3 is provided near the startposition of the extrusion cavity. A conveyor in the feed extrusioncavity 3 is a screw rod 13, and the gearbox 2 and the motor 1 drive thescrew rod to rotate. The tail end of the extrusion cavity is connectedwith a die change mechanism 5, which includes two dies: a die A 17-1 anda die B 17-2. The die A and the die B are connected with a cuttingdevice A 6-1 and a cutting device B 6-2, respectively.

The cutting device A 6-1 is connected with a sealed vertical air duct7-1 installed at the upper part thereof, then the vertical air duct 7-1is connected with a bend 8-1, and the bend 8-1 is connected with ahorizontal air duct 9-1 afterwards.

The cutting device B 6-2 is connected with a sealed vertical air duct7-2 installed at the upper part thereof, then the vertical air duct 7-2is connected with a bend 8-2, and the bend 8-2 is connected with ahorizontal air duct 9-2 afterwards.

The horizontal air ducts 9-1 and 9-2 are respectively connected with aninlet A 27-1 and an inlet B 27-2 of a three-way valve 10.

In combination with FIGS. 7 and 8 , the die change mechanism 5 includesa vertical long housing-shaped housing 14, a piston 19 is verticallyplaced in the housing 14, the top of the piston 19 is connected with adriving device 25, the driving device 25 is installed on a top plate 26,and the top plate 26 is directly connected with the housing 14.

The housing 14 includes a feeding port 20, a discharging port A 21-1 anda discharging port B 21-2. The included angle D1 between the centerlineof the feeding port 20 and the centerline of the discharging port A isabout 60°-160°, preferably about 90°-125°. The included angle D2 betweenthe centerline of the feeding port 20 and the centerline of thedischarging port B is about 60°-160°, preferably about 90°-125°.

The discharging port A is connected with a shunt 16-1, and the shunt16-1 is connected with the die A 17-1. The die A 17-1 is connected withthe cutting device A 6-1 afterwards. The cutting device A includes acutter A 18-1.

The discharging port B is connected with a shunt 16-2, and the shunt16-2 is connected with the die B 17-2. The die B 17-2 is connected withthe cutting device B 6-2 afterwards. The cutting device B includes acutter B 18-1.

The piston 19 can reciprocate up and down according to the action of thedriving device 25 in the housing at the speed of about 0.002-20 m/s,preferably about 0.01-0.1 m/s. During operation of the extruder, thepiston 19 can stay at any position inside the housing as required.

In combination with FIGS. 7-13 , the piston 19 includes a plurality ofchannels arranged at different positions above and below, each channelincludes a feeding port and one or two discharging ports. A channel A 22is connected with the discharging port A 21-1, a channel B is connectedwith the discharging port B 21-2, and a dual channel 24 is connectedwith both the discharging port A 21-1 and the discharging port B 21-2.There is one or two or more channels A; there is one or two or morechannels B; and there is zero or one or two or more dual channels.

In combination with FIGS. 19-21 again, the three-way valve 10 includestwo inlets, an inlet A 27-1 and an inlet B 27-2, and an outlet 11. Aswitch plate 28 is arranged between the inlets and the outlet, and theswitch plate 28 is connected with the driving device 29.

The switch plate 28 is provided with two channel ports: a channel port A30-1 and a channel port B 30-2. When the inlet A 27-1 is used, thechannel port A 30-1 on the switch plate 28 is aligned with the inlet A27-1, and the switch plate 28 blocks the inlet B 27-2.

When the inlet A 27-1 and the inlet B 27-2 are simultaneously used, thedriving device 29 drives the switch plate 28 to move forward, thechannel port A 30-1 on the switch plate 28 is aligned with the inlet B27-2, and the channel port B 30-2 on the switch plate is aligned withthe inlet A 27-1.

When the inlet B is used, the driving device 29 continues to drive theswitch plate 28 to move forward, the channel port B 30-2 on the switchplate 28 moves to the position of the inlet B 27-2, and the switch plate28 blocks the inlet A 27-1.

It should be pointed out that the three-way valve 10 is preferred onlyin the present embodiment. Even if the three-way valve 10 is not used,and a valve is separately provided for each air duct for independentcontrol, it does not affect the use.

The die A 17-1, or the die B 17-2, or the two dies, can be selected forproduction as required in the invention.

In combination with FIGS. 7 and 8 , when the die A 17-1 is selected forproduction, the channel A 22 on the piston moves to the feeding port 20through the action of the driving device 25, the material is extrudedinto the discharging port A through the channel A, and the die A is inan operation state at this time. Since the piston 19 blocks thedischarging port B 21-2, there is no material at the discharging port B,and the discharging port B is in a non-operation state.

After being extruded from the die A, the material enters the cuttingdevice A and is cut by the cutter A 18-1. The cut extruded productpasses through the vertical air duct 7-1, the bend 8-1 and thehorizontal air duct 9-1 upward respectively under the action of negativepressure pneumatic conveying and enters the three-way valve 10.

At this time, the channel port A 30-1 of the switch plate in thethree-way valve 10 is aligned with the inlet A 27-1, and the inlet B27-2 is blocked by the switch plate. Therefore, the negative pressureair can be transferred downward from the outlet 11 through the channelport A 30-1 all the way along the pipeline until it is delivered to thefront of the die A. Ultimately, the extruded granules are driven to moveup until reaching the outlet 11, and enter next process.

In combination with FIGS. 10 and 11 , when the die B 17-2 is selectedfor production, the channel B 23 on the piston moves to the feeding port20 through the action of the driving device 25 and the material isextruded into the discharging port B through the channel B, the die B isin an operation state at this time. Since the piston 19 blocks thedischarging port A 21-1, there is no material at the discharging port A,and the discharging port A is in a non-operation state.

After being extruded from the die B, the material enters the cuttingdevice B and is cut by the cutter B 18-2. The cut extruded productpasses through the vertical air duct 7-2, the bend 8-2 and thehorizontal air duct 9-2 upward respectively under the action of negativepressure pneumatic conveying and enters the three-way valve 10.

At this time, the channel port B 30-2 of the switch plate in thethree-way valve 10 is aligned with the inlet B 27-2, and the inlet A27-1 is blocked by the switch plate. Therefore, the negative pressureair can be transferred downward from the outlet 11 through the channelport B 30-2 all the way along the pipeline until it is delivered to thefront of the die B. Ultimately, the extruded granules are driven to moveup until reaching the outlet 11, and enter next process.

In combination with FIGS. 12 and 13 , when the die A 17-1 and the die B17-2 are selected for production simultaneously, the dual channel 24 onthe piston moves to the feeding port 20 through the action of thedriving device 25, the material is simultaneously extruded into thedischarging port A and the discharging port B through the dual channel,and the die A and the die B are simultaneously in the operation state.

After being extruded from the die A, the material enters the cuttingdevice A and is cut by the cutter A 18-1. The cut extruded productpasses through the vertical air duct 7-1, the bend 8-1 and thehorizontal air duct 9-1 upward respectively under the action of negativepressure pneumatic conveying and enters the three-way valve 10.

After being extruded from the die B, the material enters the cuttingdevice B and is cut by the cutter B 18-2. The cut extruded productpasses through the vertical air duct 7-2, the bend 8-2 and thehorizontal air duct 9-2 upward respectively under the action of negativepressure pneumatic conveying and enters the three-way valve 10.

At this time, the channel port B 30-2 of the switch plate in thethree-way valve 10 is aligned with the inlet A 27-1, and the channelport A 30-1 is aligned with the inlet B 27-2. Therefore, the negativepressure air can be transferred downward from the outlet 11 through thechannel port A 30-1 and the channel port B 30-2 all the way along thepipeline until it is delivered to the front of the two dies. Ultimately,the extruded granules at the two dies are driven to move up untilreaching the outlet 11, and enter next process.

The extruder with non-stop die change device in Embodiment 1 can achievethe switching among different dies in the production process.

When the die A is switched to the die B, the piston 19 moves down acertain position under the action of the driving device 25 during theproduction process, and the channel B 23 instead of the channel A 22 isaligned with the feeding port 20. In this way, the die A is blocked, andthe die B is opened. After the material enters the die B, the cutter Bruns to cut the material to obtain an extruded product. At this time,the inlet B 27-2 in the three-way valve 10 is opened, and the inlet A27-1 is blocked.

Conversely, when the die B is switched to the die A, it is alsopossible.

When the die A is in production, or when the die B is in production, itcan also be changed to co-production using the die A and the die B.

It should be pointed out that in the present embodiment, the adoptedpiston is a 2-position die change+1-position dual die piston, i.e., has3 channels, in which two channels can form die change positions with thedie A and the die B respectively, and one channel communicates with thedie A and the die B for use at the same time. However, based on thisprinciple, it is not limited to only the three die change positions.FIG. 15 is a structure diagram of a 2-position die change piston, i.e.,only 2 positions of the piston form die change positions with the die Aand the die B, respectively, and there is no dual-die position. FIG. 16is a structure diagram of a 3-position die change+1-position dual diepiston, that is, 2 positions are die change positions where the die A orthe die B can be changed, so that when one channel is blocked, otherchannels can replace it. Similarly, FIG. 17 is a structure diagram of a3-position die change piston. FIG. 18 is a structure diagram of a4-position die change+1-position dual die piston. In one embodiment, onthe basis of this principle, N-position die change pistons (N is greaterthan 2) and N-position die change+M-position dual die pistons (N isgreater than 2, M is greater than 1) are all available. Base on this, itis not limited to only two dies (die A, die B). As the size of the diechange device allows, setting three or more dies in the die changedevice is also an implementation that can be achieved by the principleof the invention.

In combination with FIG. 14 , the invention can control the mechanicalenergy during the production process. When the die A is used forproduction and a certain degree of misalignment is formed between thechannel A 22 and the feeding port 20, the resistance of the material atthis position becomes larger than that in alignment. If the degree ofmisalignment is larger, the resistance is larger, and the mechanicalenergy borne by the material is larger.

Therefore, the piston 19 can stay at different positions as needed tocontrol the magnitude of the mechanical energy borne by the material inthe extruder. The piston 19 can also be adjusted at different positionsin the working state of the extruder without stop. Therefore, on-lineadjustment of the mechanical energy can be realized.

Similarly, when the die B is used for production, the above function canalso be realized as same as the previous die A.

Similarly, when the die A and the die B are used for productionsimultaneously, the above function can also be realized as same as theprevious die A.

The extruder with non-stop die change device in Embodiment 1 can avoidgranule adhesion, leakage of water vapor and pollution to thesurrounding environment during the production process.

The extruded product coming out of the die, along with a large amount ofvapor, is pneumatically conveyed to next process. Because such a workingcondition is in negative pressure, the leakage of on-site vapor isavoided.

In addition, since the granules do not fall freely but are pneumaticallyconveyed, the granules do not touch each other, and the problems ofgranule deformation and adhesion are not produced.

Hereinafter, the extruder in Embodiment 1 is tested to prove that theinvention can achieve the declared beneficial effects.

The dies used in the test of Embodiment 1 are dies having the aperturesof about 3.0 mm. The main motor load current of the extruder is 90%, andthe capacity of the extruder is about 6 t/h.

The piston in the die change mechanism can reciprocate up and down inthe housing under the action of the driving device. In the presentembodiment, the moving speed of the piston is about 0.1 m/s. During theoperation of the extruder, the piston can stay at any position insidethe housing as required.

In Embodiment 1, the piston includes one channel A, one channel B andone dual channel. In Embodiment 1, the included angle D1 between thecenterline of the feeding port 20 and the centerline of the dischargingport A is about 120°. The included angle D2 between the centerline ofthe feeding port 20 and the centerline of the discharging port B is alsoabout 120°.

When Embodiment 1 is adopted, the test formula is shown in table 1. Thecrushed material has such fineness that about 95% passes through a about80-mesh sieve, about 99.5% passes through a 60-mesh sieve and 100%passes through a 50-mesh sieve. The material is first pre-cured in anordinary conditioner. The degree of gelatinization of the material afterbeing pre-cured in the conditioner is about 45%, the temperature of thematerial is 95° C., and the water content of the material is about 24%.When the material enters the extruder, it is first extruded through thedie A and cut into extruded granules through the cutter A, and theextruded granules enter the inlet A 27-1 through the sealed vertical airduct and finally enter next process from the outlet 11.

TABLE 1 Formula of material (weight percentage) Soybean meal 27 Wheatflour 25 Wheat bran 18 Rape seed cake 27 Grease 3 Total 100

The test data in Embodiment 1 includes the following:

1. First Group of Data

1) Test whether the die A can be switched to the die B without stop, andthe stable production of the extruder can also be kept after theswitching;

2) Test the time length of non-stop die change, wherein the startingpoint of the time length is when an instruction for switching the die istransmitted to a pore subsystem during the stable production process ofthe die A; and the terminating point is when the die switch iscompleted, the die B starts stable production and a qualified expandedproduct can be processed;

3) Test the maximum fluctuation range of the main motor current beforethe switch;

4) Test the maximum fluctuation range of the main motor current in theprocess of switching the die;

5) Test the comparison of the extrusion coefficients of extrudedgranules before and after the die switch;

6) Test the comparison of the volume weights of extruded granules beforeand after the die switch;

7) Test the comparison of the floating rates of the product before andafter the die switch;

8) Test the comparison of the length uniformity of extruded granulesbefore and after the die switch;

9) Visually inspect whether water vapor leaks nearby the cutting devicebefore the die switch;

10) Visually inspect whether water vapor leaks nearby the cutting deviceafter the die switch;

11) Sample 2 kg of extruded granules before the die switch to check thenumber of adhered extruded granules; and

12) Sample 2 kg of extruded granules after the die switch to check thenumber of adhered extruded granules.

2. Second Group of Data

1) Test whether the die B can be switched to the die A without stop, andthe stable production of the extruder can also be kept after theswitching;

2) Test the time length of non-stop die change, wherein the startingpoint of the time length is when an instruction for switching the die istransmitted to a pore subsystem during the stable production process ofthe die B; and the terminating point is when the die switch iscompleted, the die A starts stable production and a qualified expandedproduct can be processed.

3) Test the maximum fluctuation range of the main motor current beforethe switch;

4) Test the maximum fluctuation range of the main motor current in theprocess of switching the die;

5) Test the comparison of the extrusion coefficients of extrudedgranules before and after the die switch;

6) Test the comparison of the volume weights of extruded granules beforeand after the die switch;

7) Test the comparison of the floating rates of the product before andafter the die switch;

8) Test the comparison of the length uniformity of extruded granulesbefore and after the die switch;

9) Visually inspect whether water vapor leaks nearby the cutting devicebefore the die switch;

10) Visually inspect whether water vapor leaks nearby the cutting deviceafter the die switch;

11) Sample 2 kg of extruded granules before the die switch to check thenumber of adhered extruded granules; and

12) Sample 2 kg of extruded granules after the die switch to check thenumber of adhered extruded granules.

3. Third Group of Data

1) Test whether the die B can be switched to simultaneous operation ofthe die A and the die B without stop, and the stable production of theextruder can also be kept after the switching;

2) Test the time length of non-stop die change, wherein the startingpoint of the time length is when an instruction for switching the die istransmitted to a pore subsystem during the stable production process ofthe die B; and the terminating point is when the die switch iscompleted, the die A starts stable production and a qualified expandedproduct can be processed.

3) Test the maximum fluctuation range of the main motor current beforethe switch;

4) Test the maximum fluctuation range of the main motor current in theprocess of switching the die;

5) Test the comparison of the extrusion coefficients of extrudedgranules before and after the die switch;

6) Test the comparison of the volume weights of extruded granules beforeand after the die switch;

7) Test the comparison of the floating rates of the product before andafter the die switch;

8) Test the comparison of the length and uniformity of extruded granulesbefore and after the die switch;

9) Visually inspect whether water vapor leaks nearby the cutting devicebefore the die switch;

10) Visually inspect whether water vapor leaks nearby the cutting deviceafter the die switch;

11) Sample 2 kg of extruded granules before the die switch to check thenumber of adhered extruded granules; and

12) Sample 2 kg of extruded granules after the die switch to check thenumber of adhered extruded granules.

4. Fourth Group of Data

1) During the production process of the die A, adjust the mechanicalenergy, adjust the channel misalignment to about 20%, and check thechange of volume weight;

2) During the production process of the die A, adjust the mechanicalenergy, adjust the channel misalignment to about 30%, and check thechange of volume weight;

3) During the production process of the die A, adjust the mechanicalenergy, adjust the channel misalignment to about 40%, and check thechange of volume weight;

4) During the production process of the die B, adjust the mechanicalenergy, adjust the channel misalignment to about 20%, and check thechange of volume weight;

5) During the production process of the die B, adjust the mechanicalenergy, adjust the channel misalignment to about 30%, and check thechange of volume weight;

6) During the production process of the die B, adjust the mechanicalenergy, adjust the channel misalignment to about 40%, and check thechange of volume weight;

7) During the co-production process of the die A and the die B, adjustthe mechanical energy, adjust the channel misalignment to about 20%, andcheck the change of volume weight;

8) During the co-production process of the die A and the die B, adjustthe mechanical energy, adjust the channel misalignment to about 30%, andcheck the change of volume weight; and

9) During the co-production process of the die A and the die B, adjustthe mechanical energy, adjust the channel misalignment to about 40%, andcheck the change of volume weight.

TABLE 2 Switch die A to die B No. Test items Data  1 Time length ofnon-stop die change 15 s  2 Maximum current fluctuation before theswitch  ±8 A  3 Maximum current fluctuation during the switch ±12 A  4Maximum current fluctuation after the switch  ±9 A  5 Extrusioncoefficient of granules before the switch 1.7  6 Extrusion coefficientof granules after the switch 1.7  7 Volume weight of granules before theswitch 346 g/l  8 Volume weight of granules after the switch 340 g/l  9Floating rate of granules before the switch 100% float 10 Floating rateof granules after the switch 100% float 11 Maximum length difference ofgranules before ±0.21 mm the switch 12 Maximum length difference ofgranules after the ±0.23 mm switch 13 Whether vapor leaks nearby thecutting device No before cutting 14 Whether vapor leaks nearby thecutting device No after cutting 15 Sample 2 kg of extruded granulesbefore the die No switch to check the number of adhered extrudedgranules 16 Sample 2 kg of extruded granules after the die No switch tocheck the number of adhered extruded granules

It can be obtained by analysis based on the above test data that thetechnical application case of the invention can realize non-stop switchfrom the die A to the die B within a short time. At the same time, thedata does not fluctuate greatly during and after the switching, and thequality of the product before and after the switch can be keptconsistent.

TABLE 3 Switch die B to die A No. Test items Data  1 Time length ofnon-stop die change 15 s  2 Maximum current fluctuation before theswitch  ±7 A  3 Maximum current fluctuation during the switch ±13 A  4Maximum current fluctuation after the switch ±10 A  5 Extrusioncoefficient of granules before the switch 1.7  6 Extrusion coefficientof granules after the switch 1.7  7 Volume weight of granules before theswitch 341 g/l  8 Volume weight of granules after the switch 344 g/l  9Floating rate of granules before the switch 100% float 10 Floating rateof granules after the switch 100% float 11 Maximum length difference ofgranules before ±0.19 mm the switch 12 Maximum length difference ofgranules after the ±0.21 mm switch 13 Whether vapor leaks nearby thecutting device No before cutting 14 Whether vapor leaks nearby thecutting device No after cutting 15 Sample 2 kg of extruded granulesbefore the die switch to check the number of adhered extruded Nogranules 16 Sample 2 kg of extruded granules after the die No switch tocheck the number of adhered extruded granules

It can be obtained by analysis based on the above test data that thetechnical application case of the invention can realize non-stop switchfrom the die B to the die A within a short time. At the same time, thedata does not fluctuate greatly during and after the switching, and thequality of the product before and after the switch can be keptconsistent.

TABLE 4 Switch die B to simultaneous operation of die A and die B No.Test items Data  1 Time length of non-stop die change 15 s  2 Maximumcurrent fluctuation before the switch  ±8 A  3 Maximum currentfluctuation during the switch  ±9 A  4 Maximum current fluctuation afterthe switch ±10 A  5 Extrusion coefficient of granules before the switch1.7  6 Extrusion coefficient of granules after the switch 1.15  7 Volumeweight of granules before the switch 347 g/l  8 Volume weight ofgranules after the switch 725 g/l  9 Floating rate of granules beforethe switch 100% float 10 Floating rate of granules after the switch 100%sink 11 Maximum length difference of granules before ±0.17 mm the switch12 Maximum length difference of granules after the ±0.23 mm switch 13Whether vapor leaks nearby the cutting device No before cutting 14Whether vapor leaks nearby the cutting device No after cutting 15 Sample2 kg of extruded granules before the die switch to check the number ofadhered extruded No granules 16 Sample 2 kg of extruded granules afterthe die No switch to check the number of adhered extruded granules

It can be obtained by analysis based on the above test data that thetechnical application case of the invention can realize non-stop switchfrom the die B to simultaneous operation of the die A and the die Bwithin a short time. Floating granules with low volume weight areproduced before the switch, and 100% sinking granules are produced afterthe switching due to the increase of area of the dies. However, thedifference in the granule length of the product remains unchanged.

TABLE 5 Mechanical energy adjustment test data Volume weight of No. Testitems granules  1 Adjust the channel misalignment to 0% during 346 g/lthe production process of the die A  2 Adjust the channel misalignmentto 20% during 333 g/l the production process of the die A  3 Adjust thechannel misalignment to 30% during 322 g/l the production process of thedie A  4 Adjust the channel misalignment to 40% during 309 g/l theproduction process of the die A  5 Adjust the channel misalignment to 0%during 340 g/l the production process of the die B  6 Adjust the channelmisalignment to 20% during 331 g/l the production process of the die B 7 Adjust the channel misalignment to 30% during 318 g/l the productionprocess of the die B  8 Adjust the channel misalignment to 40% during305 g/l the production process of the die B  9 Adjust the channelmisalignment to 0% during 725 g/l the co-production process of the diesA and B 10 Adjust the channel misalignment to 20% during 685 g/l theco-production process of the dies A and B 11 Adjust the channelmisalignment to 30% during 654 g/l the co-production process of the diesA and B 12 Adjust the channel misalignment to 40% during 621 g/l theco-production process of the dies A and B

It can be obtained by analysis based on the above test data that thetechnical application case of the invention can realize on-lineadjustment of the mechanical energy. The volume weight of extrudedgranules is controlled by adjusting the percentage of misalignment ofthe channels.

By comparing the above three groups of test data, it can be concludedthat the processing technology and device applied in the technicalsolution of Embodiment 1 of the invention can realize the non-stop dieswitch, and at the same time, can realize the control of the mechanicalenergy, avoid the adhesion of the granules and avoid leakage of thevapor.

Embodiment 2

FIGS. 22-33 show a second embodiment (i.e., Embodiment 2) of an extruderwith the non-stop die change device according to the invention.

Referring to FIGS. 22-27 , in Embodiment 2, an extruder includes a base10 for supporting the entire extruder, and a motor 1 directly connectedwith the base 10, wherein the motor is directly connected with a gearbox2, the gearbox 2 is connected with a long housing-shaped multi-sectionextrusion cavity 4, and a feed extrusion cavity 3 is provided near thestart position of the extrusion cavity. The tail end of the extrusioncavity is connected with a die change device 5, which includes two dies:a die A 15-1 and a die B 15-2. The die A and the die B are connectedwith a cutting device A 6-1 and a cutting device B 6-2, respectively.

The cutting device A 6-1 is connected with a sealed vertical air duct7-1 installed at the upper part thereof, then the vertical air duct 7-1is connected with a bend 8-1, and the bend 8-1 is connected with ahorizontal air duct 9-1 afterwards.

The cutting device B 6-2 is connected with a sealed vertical air duct7-2 installed at the upper part thereof, then the vertical air duct 7-2is connected with a bend 8-2, and the bend 8-2 is connected with ahorizontal air duct 9-2 afterwards.

In combination with FIGS. 26 and 27 , the die change device 5 includes avertical cylindrical housing 12, a rotating block 13 that can rotate isarranged in the housing 12, a gearbox 16 is installed at the upper partof the rotating block 13, and the gearbox 16 is connected with therotating block 13 via a coupler 14. The gearbox 16 is fixed with thehousing 12 via a supporting rack 15. A drive motor 17 is installed abovethe gearbox. During operation, the drive motor drives the gearbox torun, and the drives the rotating block to rotate via the coupler. In theembodiment, the gearbox 16 is a decelerator.

The housing 12 includes a feeding port 23, a discharging port A 20-1 anda discharging port B 20-2. The included angle between the centerline ofthe feeding port 23 and the centerline of the discharging port A 20-1 isD1; and the included angle between the centerline of the feeding port 23and the centerline of the discharging port B 20-2 is D2. D1 is 85°-125°,preferably 120° and 90°, and D1 is absolutely equal to D2, or theabsolute value of the angle value of D1-D2 is less than or equal to 5°.

The discharging port A is connected with a shunt 14-1, and the shunt14-1 is connected with the die A 15-1. The die A 15-1 is connected withthe cutting device A 6-1 afterwards. The cutting device A includes acutter A 16-1.

The discharging port B is connected with a shunt 14-2, and the shunt14-2 is connected with the die B 15-2. The die B 15-2 is connected withthe cutting device B 6-2 afterwards. The cutting device B includes acutter B 16-2.

The rotating block 13 can rotate horizontally in the housing 12, and therotating power of the rotating block 13 comes from the drive motor andthe gearbox installed at the upper part of the housing. The angularvelocity of the rotating block 13 is 0.08°-160° m/s, preferably8°-40°/s. During the operation of the extruder, the rotating block 13can stay at any position inside the housing 12 as required and can beheld.

The rotating block 13 includes two access channels: a channel A 21 and achannel B 22. The included angle between the channel A and the channel Bis equal to D1.

As shown in FIG. 28 , when the channel A 21 is opposite to thedischarging port 20-1, the channel B 22 is just opposite to the feedingport 23, and the rotating block 13 just blocks the discharging port B20-2.

During the production process, the material enters the channel B fromthe feeding port 23. Since the channel B is connected with the channelA, the material enters the discharging port A 20-1 along the twoconnected channels. The discharging port A is connected with the die A15-1. At this time, the die A can work. The rotating block 13 blocks thedischarging port B 20-2, so the material will not enter the dischargingport B, the material will not be extruded from the die B connected withthe discharging port B, and the die B is in a non-operation state.

As shown in FIG. 30 , when the rotating block 13 rotates and the channelA 21 is just opposite to the feeding port 23, the rotating block stopsmoving and is fixed. At this time, the channel B 22 is just opposite tothe discharging port B 20-2, and the rotating block 13 just blocks thedischarging port A 20-1.

During the production process, when the rotating block rotates to theabove position, the material enters the channel A from the feeding port23. Since the channel A is connected with the channel B, the materialenters the discharging port B 20-2 along the two connected channels. Thedischarging port B 20-2 is connected with the die B 15-2. At this time,the die B can work. The rotating block 13 blocks the discharging port A20-1, so the material will not enter the discharging port A, thematerial will not be extruded from the die A connected with thedischarging port A, and the die A is in a non-operation state.

In combination with FIGS. 28 and 30 , when the die A 17-1 is selectedfor production, the channel A 22 on the rotating block moves to thefeeding port 20 through the action of the driving device 25, thematerial is extruded into the discharging port A through the channel A,and the die A is in an operation state at this time. Since the rotatingblock 19 blocks the discharging port B 21-2, there is no material at thedischarging port B, and the discharging port B is in a non-operationstate.

Through the rotation of the rotating block as described above, theoperation switching relationship between the die A and the die B isrealized, and the change of the die is also realized. At the same time,the rotating block rotates the angle D1 within 0.1 to 10 seconds, whichis relatively short. Thus, non-stop die change can be realized.

Referring to FIG. 32 , when the rotating block 13 is changed into athree-channel rotating block 24, the three-channel rotating block 24simultaneously has a rotatable function. The rotating block 24 includesa channel I 25, a channel II 26 and a channel III 27. When the channel I25 is opposite to the feeding port 23, the channel II 26 is justopposite to the discharging port B 20-2, and the channel III 27 is justopposite to the discharging port A 20-1.

Since the channel I 25, the channel II 26 and the channel III 27communicate with each other, during production, when the material flowsin from the feeding port 23, the material will enter the die A throughthe channel III 27 and enter the die B through the channel II 26. Inthis way, the co-production function of the two dies is realized.

In combination with FIGS. 29 and 31 , the invention can control themechanical energy during the production process. When the die A is usedfor production, a certain degree of misalignment can be formed betweenthe discharging port A 20-1 and the channel A 21 through the rotation ofthe rotating block. Compared to alignment, the resistance of thematerial at this position increases. If the degree of misalignment islarger, the resistance is larger and the mechanical energy borne by thematerial is larger.

Therefore, the rotating block 13 can stay at different positions asneeded to control the magnitude of the mechanical energy borne by thematerial in the extruder. The rotating block 13 can also be adjusted atdifferent positions in the working state of the extruder without stop.Therefore, on-line adjustment of the mechanical energy can be realized.

Similarly, when the die B is used for production, the above function canalso be realized as same as the previous die A.

In combination with FIG. 33 , similarly, when the die A and the die Bare used for production simultaneously, the above function can also berealized as same as the previous die A.

The extruder with non-stop die change device in Embodiment 2 can avoidgranule adhesion, leakage of water vapor and pollution to thesurrounding environment during the production process.

The extruded product coming out of the die, along with a large amount ofvapor, is pneumatically conveyed to next process. Because such a workingcondition is in negative pressure, the leakage of on-site vapor isavoided.

In addition, since the granules do not fall freely but are pneumaticallyconveyed, the granules do not touch each other, and the problems ofgranule deformation and adhesion are not produced.

Hereinafter, the extruder in Embodiment 2 is tested to prove that theinvention can achieve the declared beneficial effects.

The dies used in the test of Embodiment 2 are dies having the aperturesof 3.0 mm. The main motor load current of the extruder is 90%, and thecapacity of the extruder is 6 t/h.

The rotating block in the die change device can reciprocate up and downin the housing under the action of the driving device. In Embodiment 2,the rotating speed of the rotating block is 30°/s. During the operationof the extruder, the rotating block can stay at any position inside thehousing as required.

In Embodiment 2, the included angle D1 between the centerline of thefeeding port and the centerline of the discharging port A is 120°. Theincluded angle D2 between the centerline of the feeding port 20 and thecenterline of the discharging port B is also 120°.

Embodiment 2 involves two steps, wherein the first step is to test diechange data using the rotating block of two channels having the includedangle of 120°; and the second step is to test production data using therotating block of three channels having the included angles of 120°.

When Embodiment 2 is adopted, the test formula is shown in table 6. Thecrushed material has such fineness that 95% passes through a 80-meshsieve, 99.5% passes through a 60-mesh sieve and 100% passes through a50-mesh sieve. The material is first pre-cured in an ordinaryconditioner. The degree of gelatinization of the material after beingpre-cured in the conditioner is 45%, the temperature of the material is95° C., and the water content of the material is 24%. When the materialenters the extruder, it is first extruded through the die A and cut intoextruded granules through the cutter A, and the extruded granules enterthe inlet A through the sealed vertical air duct and finally enter nextprocess from the outlet.

TABLE 6 Formula of material (weight percentage) Soybean meal 27 Wheatflour 25 Wheat bran 18 Rape seed cake 27 Grease 3 Total 100

In Embodiment 2, the test is divided into two steps, wherein the firststep is dual-channel test, and the second step is three-channel test.The test data includes the following:

1. First Group of Data (Dual-Channel Test)

13) Test whether the die A can be switched to the die B without stop,and the stable production of the extruder can also be kept after theswitching;

14) Test the time length of non-stop die change, wherein the startingpoint of the time length is when an instruction for switching the die istransmitted to a pore subsystem during the stable production process ofthe die A; and the terminating point is when the die switch iscompleted, the die B starts stable production and a qualified expandedproduct can be processed.

15) Test the maximum fluctuation range of the main motor current beforethe switch;

16) Test the maximum fluctuation range of the main motor current in theprocess of switching the die;

17) Test the comparison of the extrusion coefficients of extrudedgranules before and after the die switch;

18) Test the comparison of the volume weights of extruded granulesbefore and after the die switch;

19) Test the comparison of the floating rates of the product before andafter the die switch;

20) Test the comparison of the length uniformity of extruded granulesbefore and after the die switch;

21) Visually inspect whether water vapor leaks nearby the cutting devicebefore the die switch;

22) Visually inspect whether water vapor leaks nearby the cutting deviceafter the die switch;

23) Sample 2 kg of extruded granules before the die switch to check thenumber of adhered extruded granules;

24) Sample 2 kg of extruded granules after the die switch to check thenumber of adhered extruded granules;

25) During the production process of the die B, adjust the mechanicalenergy, adjust the channel misalignment to 20%, and check the change ofvolume weight;

26) During the production process of the die B, adjust the mechanicalenergy, adjust the channel misalignment to 30%, and check the change ofvolume weight; and

27) During the production process of the die B, adjust the mechanicalenergy, adjust the channel misalignment to 40%, and check the change ofvolume weight.

TABLE 7 Switch die A to die B No. Test items Data  1 Time length ofnon-stop die change 2.2 s  2 Maximum current fluctuation before theswitch  ±8 A  3 Maximum current fluctuation during the switch ±12 A  4Maximum current fluctuation after the switch  ±9 A  5 Extrusioncoefficient of granules before the switch 1.7  6 Extrusion coefficientof granules after the switch 1.7  7 Volume weight of granules before theswitch 346 g/l  8 Volume weight of granules after the switch 340 g/l  9Floating rate of granules before the switch 100% float 10 Floating rateof granules after the switch 100% float 11 Maximum length difference ofgranules before the ±0.21 mm switch 12 Maximum length difference ofgranules after the ±0.23 mm switch 13 Whether vapor leaks nearby thecutting device before No cutting 14 Whether vapor leaks nearby thecutting device after No cutting 15 Sample 2 kg of extruded granulesbefore the die No switch to check the number of adhered extrudedgranules 16 Sample 2 kg of extruded granules after the die No switch tocheck the number of adhered extruded granules 17 Adjust the channelmisalignment to 0% during the 340 g/l production process of the die B 18Adjust the channel misalignment to 20% during the 331 g/l productionprocess of the die B 19 Adjust the channel misalignment to 30% duringthe 318 g/l production process of the die B 20 Adjust the channelmisalignment to 40% during the 305 g/l production process of the die B

It can be obtained by analysis based on the above test data that thetechnical application case of the invention can realize non-stop switchfrom the die A to the die B within a short time. At the same time, thedata does not fluctuate greatly during and after the switching, and thequality of the product before and after the switch can be keptconsistent.

2. Second Group of Data (Dual-Channel Test)

13) Test whether the die B can be switched to the die A without stop,and the stable production of the extruder can also be kept after theswitching;

14) Test the time length of non-stop die change, wherein the startingpoint of the time length is when an instruction for switching the die istransmitted to a pore subsystem during the stable production process ofthe die B; and the terminating point is when the die switch iscompleted, the die A starts stable production and a qualified expandedproduct can be processed.

15) Test the maximum fluctuation range of the main motor current beforethe switch;

16) Test the maximum fluctuation range of the main motor current in theprocess of switching the die;

17) Test the comparison of the extrusion coefficients of extrudedgranules before and after the die switch;

18) Test the comparison of the volume weights of extruded granulesbefore and after the die switch;

19) Test the comparison of the floating rates of the product before andafter the die switch;

20) Test the comparison of the length uniformity of extruded granulesbefore and after the die switch;

21) Visually inspect whether water vapor leaks nearby the cutting devicebefore the die switch;

22) Visually inspect whether water vapor leaks nearby the cutting deviceafter the die switch;

23) Sample 2 kg of extruded granules before the die switch to check thenumber of adhered extruded granules;

24) Sample 2 kg of extruded granules after the die switch to check thenumber of adhered extruded granules;

25) During the production process of the die A, adjust the mechanicalenergy, adjust the channel misalignment to 20%, and check the change ofvolume weight;

26) During the production process of the die A, adjust the mechanicalenergy, adjust the channel misalignment to 30%, and check the change ofvolume weight; and

27) During the production process of the die A, adjust the mechanicalenergy, adjust the channel misalignment to 40%, and check the change ofvolume weight.

TABLE 8 Switch die B to die A No. Test items Data  1 Time length ofnon-stop die change 2.2 s  2 Maximum current fluctuation before theswitch  ±7 A  3 Maximum current fluctuation during the switch ±13 A  4Maximum current fluctuation after the switch ±10 A  5 Extrusioncoefficient of granules before the switch 1.7  6 Extrusion coefficientof granules after the switch 1.7  7 Volume weight of granules before theswitch 341 g/l  8 Volume weight of granules after the switch 344 g/l  9Floating rate of granules before the switch 100% float 10 Floating rateof granules after the switch 100% float 11 Maximum length difference ofgranules before ±0.19 mm the switch 12 Maximum length difference ofgranules after the ±0.21 mm switch 13 Whether vapor leaks nearby thecutting device No before cutting 14 Whether vapor leaks nearby thecutting device No after cutting 15 Sample 2 kg of extruded granulesbefore the die No switch to check the number of adhered extrudedgranules 16 Sample 2 kg of extruded granules after the die No switch tocheck the number of adhered extruded granules 17 Adjust the channelmisalignment to 0% during 346 g/l the production process of the die A 18Adjust the channel misalignment to 20% during 333 g/l the productionprocess of the die A 19 Adjust the channel misalignment to 30% during322 g/l the production process of the die A 20 Adjust the channelmisalignment to 40% during 309 g/l the production process of the die A

It can be obtained by analysis based on the above test data that thetechnical application case of the invention can realize non-stop switchfrom the die B to the die A within a short time. At the same time, thedata does not fluctuate greatly during and after the switching, and thequality of the product before and after the switch can be keptconsistent.

3. Third Group of Data (Three-Channel Test)

13) Test whether the extruder can realize stable production when the dieA and the die B work at the same time;

14) Test the maximum fluctuation range of the main motor current in theproduction process;

15) Test the comparison of the extrusion coefficients of extrudedgranules of the die A and the die B;

16) Test the comparison of the volume weights of extruded granules ofthe die A and the die B;

17) Test the comparison of the floating rates of extruded granules ofthe die A and the die B;

18) Test the comparison of the length uniformity of extruded granules ofthe die A and the die B;

19) Visually inspect whether water vapor leaks nearby the cuttingdevice;

20) Sample 2 kg of extruded granules, before the die A is used, to checkthe number of adhered extruded granules;

21) Sample 2 kg of extruded granules, before the die B is used, to checkthe number of adhered extruded granules;

22) During the co-production process of the die A and the die B, adjustthe mechanical energy, adjust the channel misalignment to 20%, and checkthe change of volume weight;

23) During the co-production process of the die A and the die B, adjustthe mechanical energy, adjust the channel misalignment to 30%, and checkthe change of volume weight; and

24) During the co-production process of the die A and the die B, adjustthe mechanical energy, adjust the channel misalignment to 40%, and checkthe change of volume weight.

TABLE 9 Switch die B to simultaneous operation of die A and die B No.Test items Data  1 Whether stable production can be realized OK  2Maximum current fluctuation during the ±8 A production process  3Extrusion coefficient with the use of die A 1.71  4 Extrusioncoefficient with the use of die B 1.72  5 Volume weight of granules withthe use of die A 726 g/l  6 Volume weight of granules with the use ofdie B 725 g/l  7 Sink rate with the use of die A 100%  8 Sink rate withthe use of die B 100%  9 Length average value of 100 granules with the4.31 mm use of die A 10 Length average value of 100 granules with the4.35 mm use of die B 11 Whether vapor leaks nearby the cutting device No12 Sample 2 kg of extruded granules, when the die A No is used, to checkthe number of adhered extruded granules 13 Sample 2 kg of extrudedgranules, when the die B No is used, to check the number of adheredextruded granules 14 Adjust the channel misalignment to 0% during 725g/l the co-production process of the dies A and B 15 Adjust the channelmisalignment to 20% during 685 g/l the co-production process of the diesA and B 16 Adjust the channel misalignment to 30% during 654 g/l theco-production process of the dies A and B 17 Adjust the channelmisalignment to 40% during 621 g/l the co-production process of the diesA and B

It can be obtained by analysis based on the above test data that thetechnical application case of the invention can realize simultaneousoperation of the die A and the die B. At the same time, the mechanicalenergy can be controlled.

By comparing the above three groups of test data, it can be concludedthat the processing technology and device applied in the technicalsolution of Embodiment 2 of the invention can realize the non-stop dieswitch, and at the same time, can realize the control of the mechanicalenergy, avoid the adhesion of the granules and avoid leakage of thevapor.

The foregoing description of the exemplary embodiments of the inventionhas been presented only for the purposes of illustration and descriptionand is not intended to be exhaustive or to limit the invention to theprecise forms disclosed. Many modifications and variations are possiblein light of the above teaching.

The embodiments were chosen and described in order to explain theprinciples of the invention and their practical application so as toenable others skilled in the art to utilize the invention and variousembodiments and with various modifications as are suited to theparticular use condied. Alternative embodiments will become apparent tothose skilled in the art to which the invention pertains withoutdeparting from its spirit and scope. Accordingly, the scope of theinvention is defined by the appended claims rather than the foregoingdescription and the exemplary embodiments described therein.

What is claimed is:
 1. An extruder with a non-stop die change device,comprising: an extrusion cavity, a feeding port located at an upper partin the extrusion cavity, a die change device located at an outlet of theextrusion cavity, and a conveyor arranged in the extrusion cavity forconveying a material to the die change device; wherein the die changedevice comprises a housing, a movable block located in the housing, adriving device for driving the movable block, a first die connected to aside wall of the housing, and a second die connected to the side wall ofthe housing; the first die is provided with a first channel thatpenetrates the first die and communicates with an interior of thehousing; the second die is provided with a second channel thatpenetrates the second die and communicates with the interior of thehousing; the outlet of the extrusion cavity is connected to the sidewall of the housing and communicates with the interior of the housing;and the housing is a vertical housing that is perpendicular to the firstchannel and the second channel; and wherein a transfer channel isprovided in the movable block, and the movable block is driven by thedriving device to move at a first position to a second position; whenthe movable block moves to the first position in the housing, thetransfer channel communicates to the extrusion cavity with the firstchannel; and when the movable block moves to the second position in thehousing, the transfer channel communicates to the extrusion cavity withthe second channel; and wherein the movable block is a piston verticallyplaced inside the housing and vertically movable in the housing alongwith a housing direction that is perpendicular to the first channel andthe second channel.
 2. The extruder with the non-stop die change deviceaccording to claim 1, wherein at least one first transfer channel and atleast one second transfer channel are provided in the piston; when thepiston moves to the first position in the housing, the first transferchannel communicates to the extrusion cavity with the first channel; andwhen the piston moves to the second position in the housing, the secondtransfer channel communicates to the extrusion cavity with the secondchannel.
 3. The extruder with the non-stop die change device accordingto claim 2, wherein at least one third transfer channel is provided inthe piston; when the piston moves to a third position in the housing,the third transfer channel communicates to the extrusion cavity with thefirst channel and the second channel simultaneously.
 4. The extruderwith the non-stop die change device according to claim 2, wherein thefirst transfer channel comprises a first inlet and a first outlet, thesecond transfer channel comprises a second inlet and a second outlet,and the side wall of the housing is provided with a feeding port forconnecting the interior of the housing with the outlet of the extrusioncavity, a first discharging port for connecting the interior of thehousing with the first transfer channel and a second discharging portfor connecting the interior of the housing with the second transferchannel; a included angle D1 between a centerline of the feeding port onthe housing and a centerline of the first discharging port is 60°-160°;and a included angle D2 defined between a centerline of the feeding portand a centerline of the second discharging port is 60°-160°.
 5. Theextruder with the non-stop die change device according to claim 4,wherein the included angle D1 between the centerline of the feeding porton the housing and the centerline of the first discharging port is90°-125°; and the included angle D2 between the centerline of thefeeding port and the centerline of the second discharging port is90°-125°.
 6. An extruder with the non-stop die change device comprising:an extrusion cavity, an input port located at an upper part in theextrusion cavity, a die change device located at an outlet of theextrusion cavity, and a conveyor arranged in the extrusion cavity forconveying a material to the die change device; wherein the die changedevice comprises a housing, a movable block located in the housing, adriving device for driving the movable block, a first die connected to aside wall of the housing, and a second die connected to the side wall ofthe housing; the first die is provided with a first channel thatpenetrates the first die and communicates with an interior of thehousing; the second die is provided with a second channel thatpenetrates the second die and communicates with the interior of thehousing; and the outlet of the extrusion cavity is connected to the sidewall of the housing and communicates with the interior of the housing;wherein a transfer channel is provided in the movable block, and themovable block is driven by the driving device to move at a firstposition to a second position; when the movable block moves to the firstposition in the housing, the transfer channel communicates to theextrusion cavity with the first channel; and when the movable blockmoves to the second position in the housing, the transfer channelcommunicates to the extrusion cavity with the second channel; whereinthe movable block is a rotating block rotatable in the housing; whereinin operation, when the rotating block rotates to the first position, afirst port communicates with the extrusion cavity and a second portcommunicates with the first channel; and when the rotating block rotatesto the second position, the second port communicates with the extrusioncavity, and the first port communicates with the second channel; andwherein when the first die and the second die are simultaneously usedfor production, the rotating block is replaced with a three-way rotatingblock that is provided with a three-way transfer channel comprising achannel I, and a channel II and a channel III that communicate with thechannel I at the same time, and when the driving device drives thethree-way rotating block to rotate till the channel I communicates withthe extrusion cavity, the channel II communicates with the first channeland the channel III communicates with the second channel.
 7. Theextruder with the non-stop die change device according to claim 6,wherein the side wall of the housing is provided with a feeding port forconnecting the interior of the housing with the outlet of the extrusioncavity, a first discharging port for connecting the interior of thehousing with the first transfer channel and a second discharging portfor connecting the interior of the housing with the second transferchannel; a included angle D1 between a centerline of the feeding port onthe housing and a centerline of the first discharging port is 85°-125°;and a included angle between a centerline of the feeding port and acenterline of the second discharging port is D2, D2 is equal to D1 orthe absolute value of the angle value of D1-D2 is less than or equal to5°.
 8. The extruder with the non-stop die change device according toclaim 7, wherein the included angle D1 between the centerline of thefeeding port on the housing and the centerline of the first dischargingport is 120° or 90°.
 9. The extruder with the non-stop die change deviceaccording to claim 1, further comprising a first cutting deviceconnected with the first die, a second cutting device connected with thesecond die, a first air duct connected with the first cutting device,and a second air duct connected with the second cutting device.
 10. Theextruder with the non-stop die change device according to claim 9,further comprising a three-way valve connected with the first air ductand the second air duct at the same time, wherein the three-way valve isprovided with a first inlet, a second inlet and a switch valve outlet,the first inlet communicates with the first air duct, and the secondinlet communicates with the second air duct.
 11. The extruder with thenon-stop die change device according to claim 10, wherein the three-wayswitch comprises a switch plate located between the two inlets and theswitch valve outlet and a driving device for driving the switch plate,and the switch plate is provided with a first channel port and a secondchannel port; when the first inlet is used, the switch plate is drivento enable the first channel port to be aligned with the first inlet, andthe switch plate blocks the second inlet; when the first inlet and thesecond inlet are used simultaneously, the driving device drives theswitch plate to move forward, so that the first channel port is alignedwith the second inlet and the second channel port is aligned with thefirst inlet; and when the second inlet is used, the driving devicecontinues to drive the switch plate to move forward, the second channelport is aligned with the second inlet, and the switch plate blocks thefirst inlet.
 12. The extruder with the non-stop die change deviceaccording to claim 11, wherein the first air duct comprises a firstvertical air duct connected with the first cutting device and extendingupward from the first cutting device, a first bend connected to theupper end of the first vertical air duct and bent to the horizontaldirection, and a first horizontal air duct connected to the horizontalend of the first bend and continuously horizontally extending to connectwith the first inlet; and the second air duct comprises a secondvertical air duct connected with the second cutting device and extendingupward from the second cutting device, a second bend connected to theupper end of the second vertical air duct and bent to the horizontaldirection, and a second horizontal air duct connected to the horizontalend of the second bend and continuously horizontally extending toconnect with the second inlet.
 13. The extruder with the non-stop diechange device according to claim 1, wherein the conveyor in theextrusion cavity is a screw rod, and the rear end of the extrusioncavity is connected with a gearbox and a motor for driving the screw rodto rotate.